(i) Recurrent publications (number of issues in parentheses): Energy and Transport Newsletter (4); International Rivers and Lakes Newsletter (4); Natural Resources Forum (quarterly) (8); policy instruments for sustainable development (1);
i) Publicaciones periódicas (la cantidad de números figura entre paréntesis): Energy and Transport Newsletter (4); International Rivers and Lakes Newsletter (4); Natural Resources Forum (trimestral) (8); instrumentos de política para el desarrollo sostenible (1);